scholarly journals T-WiEYE: An early-age concrete strength development monitoring and miniaturized wireless impedance sensing system

2011 ◽  
Vol 10 ◽  
pp. 484-489 ◽  
Author(s):  
C. Providakis ◽  
E. Liarakos
2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
C. P. Providakis ◽  
E. V. Liarakos ◽  
E. Kampianakis

Monitoring the concrete early-age strength gain at any arbitrary time from a few minutes to a few hours after mixing is crucial for operations such as removal of frameworks, prestress, or cracking control. This paper presents the development and evaluation of a potential active wireless USB sensing tool that consists of a miniaturized electromechanical impedance measuring chip and a reusable piezoelectric transducer appropriately installed in a Teflon-based enclosure to monitor the concrete strength development at early ages and initial hydration states. In this study, the changes of the measured electromechanical impedance signatures as obtained by using the proposed sensing system during the whole early-age concrete hydration process are experimentally investigated. It is found that the proposed electromechanical impedance (EMI) sensing system associated with a properly defined statistical index which evaluates the rate of concrete strength development is very sensitive to the strength gain of concrete structures from their earliest stages.


2016 ◽  
Vol 10 (1) ◽  
pp. 363-368 ◽  
Author(s):  
Zhenyang Zhu ◽  
Weimin Chen ◽  
Zhiqiang Xie ◽  
Guoxin Zhang

The adiabatic temperature rise of early-age concrete can be precisely tested by the device. However, the insufficient accuracy of testing device can lead to inaccurate measurements of adiabatic temperature rise of later-age concrete. The purpose of this paper is to create a model to predict the hydration heat of later-age concrete. Based on the previous studies, it is known that the heat release of the concrete is accomplished with the increment of the concrete strength and concrete strength can be accurately measured. Thus, a preliminary later-age hydration heat model was established. The correction of the model was verified through experiments.


2011 ◽  
Vol 368-373 ◽  
pp. 1535-1538
Author(s):  
Nan Zhao ◽  
Wen Yan

This paper analyses the characteristics of resistance of structural components, puts forward the concept of early resistance force of structural components, and discuss the main factors which affect it based on the field measurement investigation and theoretical analysis. Besides, in the paper the reduction factor is applied to reflect time-varying features of early-age concrete strength, and utilization coefficient of concrete strength is utilized to present the influence of early time-varying features of cohesive action on resistance. The paper finally deduces the formula of early-age resistance force of typical flexural member, and gives the time-changing law of early resistance by using a case.


2020 ◽  
Vol 17 (2) ◽  
pp. 1032-1036
Author(s):  
Nur Nadhira Abdul Rasid ◽  
Abdul Rahman Mohd. Sam ◽  
Azman Mohamed ◽  
Nor Hasanah Abdul Shukor Lim ◽  
Zaiton Abdul Majid ◽  
...  

Blended concrete has later strength development with long maturity strength development. An accelerator is thus needed to enhance the early strength development of concrete. This paper shows the combination of ground palm oil fuel ash and eggshell powder that was designed for later and early strength development, respectively. Two types of eggshell powder were utilised in concrete: uncarbonised eggshell powder and decarbonised eggshell powder. The study was initiated with compression test for concrete curing at age 1, 3, 7, and 28 days followed by rapid evaluation test of setting time to investigate the preliminary performance between materials. The results revealed decarbonised eggshell powder as a high accelerator that can improve the early age of concrete strength development. Meanwhile, despite showing the best performance, uncarbonised eggshell powder is a very low accelerator thus not fit the purpose. In conclusion, the combination of ground palm oil fuel ash (rich with silica oxide) and decarbonised eggshell powder (rich with calcium oxide) provided dual function, where ground palm oil fuel ash and decarbonised eggshell powder took later and early strength development, respectively. The combination between silica oxide and calcium oxide in cementitious materials has potential to be utilised to enhance the early age of a blended concrete strength development.


2011 ◽  
Vol 105-107 ◽  
pp. 976-980
Author(s):  
Yan Wang ◽  
Sheng Xing Wu ◽  
Shuo Chen ◽  
Yao Wang ◽  
Bao Long Wei

A total of 18 specimens’ damage processes of concrete under split load in 1d, 3d, 5d, 7d, 14d and 28d ages are monitored by acoustic emission (AE) technique and corresponding typical AE characteristics are summarized. The results show that splitting tensile strength of concrete and the number of AE hits are both showing a gradual increase with the growth of age. During the process of splitting failure of concrete specimens in 14d and 28d, AE hits in higher duration and amplitude are collected, It shows that the older concretes tends to release more energy, at last, AE parameters which are in higher correlation with the development of mechanical properties for early age concrete are given. Related research conclusions can provide the foundation for the research of strength development and damage mechanism of early age concretes.


2018 ◽  
Vol 195 ◽  
pp. 01025
Author(s):  
Suryawan Murtiadi ◽  
Akmaluddin Akmaluddin ◽  
Buan Anshari ◽  
Suparjo Suparjo

Conventionally, curing is performed by moisturizing concrete periodically when the fresh concrete is still undergoing chemical reaction processes. This study is focused on early age concrete strength treated with special curing of early heating treatment and steaming. The addition of chemical accelerator and normal curing are also examined. Tests were conducted on normal and high strength concrete specimens. Treatments of the test specimens with steaming and early heating were carried out for 3 and 8 hours, respectively, at a temperature of about 70° C. Test results showed that concrete compressive strengths gained in 3-days compared to 28-days under normal curing, chemical accelerator, steam curing, and elevated temperature curing were 39%, 50%, 64% and 59%, respectively. While in 7-days were 66%, 75%, 80% and 83%, respectively. And in 14- days were 87%, 91%, 93% and 93%, respectively. For high-strength concrete, the compressive strengths gained in 3-days were 37%, 62%, 68% and 71%, respectively. The strengths in 7-days were 65%, 77%, 83% and 82%, respectively. And in 14-days were 85%, 89%, 90% and 93%, respectively. Test results indicated that the additions of chemical accelerator, steam and elevated temperature curing in order to obtain the high early age concrete strengths are highly recommended.


Optik ◽  
2016 ◽  
Vol 127 (5) ◽  
pp. 2983-2987 ◽  
Author(s):  
Jian Chen ◽  
Peng Li ◽  
Gangbing Song ◽  
Zhang Ren

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